I n each set below, two of the sentences are punctuated correctly. Your job is to pick out the one sentence that is not correctly punctuated.
A.
Harbor Springs is now a summer resort for the affluent but a century ago it was the Indian village of my Ottawa ancestors.
B.
Harbor Springs is now a summer resort for the affluent , but a century ago it was the Indian village of my Ottawa ancestors.
C.
Harbor Springs is now a summer resort for the affluent ; a century ago it was the Indian village of my Ottawa ancestors.